Heating, ventilating and air conditioning systems



S. C. ZINMAN A ril 7, 1964 HEATING, VENTILATING AND AIR CONDITIONING SYSTEMS 2 Sheets-Sheet 2 Filed March 24, 1960 2 a y w M Ill-I'll i United States Patent Ofiice 3,127,927 Patented Apr. 7, 1964 I 3,127,927 HEATHQG, VENTELATHNG AND Am CONDITIONENG SYSTEMS Samuel C. Zinman, Far Roekaway, N.Y., assignor to DY/liliin Corp, New York, N.Y., a corporation of New Filed Mar. 24, 1%9, Ser. No. 17,418 2 Claims. ((11. 16522) This invention relates generally to the heating and cooling systems of building structure, and more particularly to improved systems which may be incorporated into existing older buildings to achieve increased efficiency of heat transfer, disposal of condensate wastes and the like.

The systems are particularly advantageous in older multi-unit buildings, such as office buildings and apartment houses.

In the modernization of such buildings, it is conventional to install individual air-conditioning units rather than to air-condition the entire building from a central cooling source. These units normally project outwardly over the street, and during operation on humid days, water condensate from the evaporator system usually fills the evaporator pan to a level where the over flow drips or runs onto the street.

For reasons of economy, many older and newer buildings are equipped with what is referred to in the art as a one-pipe steam system in which steam emanating from the boiler travels along a horizontally disposed steam main to a plurality of risers, there being a plurality of radiators or similar heating elements fed from the risers on each of the floors of the builidng. Upon commencement of operation, steam generated in the boiler travels along the main and up through the risers into the radiators. As the steam condenses in the radiators, with passage of time, the water condensate will flow back through the risers, to the main, and ultimately back to the boiler. However, the degree of condensation varies from radiator to radiator depending upon environmental conditions, the distance from the riser which feeds it, and the presence or absence of an automatic valve on the individual radiator. Much water remains in the radiator below the steam which is condensing, interfering with efiicient operation of the radiators and altering the level of water within the boiler. Where automatic valves are employed on individual radiators, the problem of waterhammer is common, and difliculty is encountered in maintaining a steady flow of heat to the radiators in response to a constant demand.

It is normally not economical to install additional pipes in the older biuldings and some new buildings, and it is accordingly among the principal objects of the present invention to provide an improved system which may be incorporated into the existing and new construction of the building whereby the above-mentioned disadvantages may be substantially eliminated.

Another object of the invention lies in the provision of a system in which the heating efficiency may be substantially improved by periodic return of collected condensate to the boiler.

Another object of the invention lies in the provision of means whereby steam risers may be utilized in summer to collect air-conditioner condensate in such manner as to permit the same to be disposed of to the sanitary system of the building.

Still another object of the invention lies in the provision of structure of the class described and possessed of the above advantages in which the cost of fabrication and installation may be of a reasonably low order, with consequent wide sale, distribution and use.

A feature of the invention lies in its ready applicability to radiator locations which are disposed below the main steam line, as for example in a basement or sub-cellar of a building.

Another feature of the invention lies in the provision of an indiivdual unit which may be installed at suitable points in the existing and new heating systems for the purpose of collecting condensate, and pumping the same at periodic intervals to return the same to existing steam mains and ultimately to the boiler.

These objects and features, as well as other incidental ends and advantages, will more fully appear in the progress of the following disclosure, and be pointed out in the appended cla'uns.

In the drawings, to which reference will be made in the specification, similar reference characters have been employed to designate corresponding parts throughout the several views.

FIGURE 1 is a schematic diagram showing the invention.

FIGURE 2 is a vertical sectional view showing an indiviciual condensate pump unit employed in the invention as a component part thereof.

FIGURE 3 is a vertical transverse sectional view as seen from the plane 4--4 in FIGURE 2.

FIGURE 4 is an enlarged fragmentary sectional view showing a fitting installed upon a conventional steam riser and employed in conjunction with the units shown in FIGURES 2 and 3.

Turning to the invention, as seen in FIGURE 1, there is schematically illustrated a typical installation in an older and new multi-unit building employing a one-pipe steam system. On the basement level, generally indicated by reference character 11, there is a conventional heating assembly which generates and supplies heat to outlets on the basement level, a first floor level 12, a second floor level 13, a third floor level 14, and a fourth floor level 15.

As is well known in the art, the boiler, generally indicated by reference character 17 includes circulating pipes 18 which feed steam to a horizontally disposed steam main 19, and thence through valves 20 to a plurality of risers, two of which are indicated by reference characters 21 and 22. A similar riser 23 may be employed to service units disposed below the main 19.

Extending from the risers 21 and 22, on each of the floors 12-15 are short horizontal conduits 25 leading to short vertical conduits 26 which service individual radiators. The vertical conduits 26 are provided with special return fittings 27, described in greater detail at a point later in this specification, and lead to heating elements in the form of radiators, convectors and the like, generally indicated by reference character 29. When employing a one-pipe system, the outlet 30 of each of the radiators 29 is normally equipped with a breathing valve which permits air to escape, while stopping steam vapor and condensate which collects in the lower part of the radiator until it ultimately overflows to return down the risers 21 or 22. In the present embodiment, the outlet 30 is connected to a float and thermostatic trap of a type well known in the art, and thence to a float pump unit 31 and 32, described in greater detail hereinbelow. The trap 31, where a float and thermostatic type is employed, is responsive to the temperature of fluids flowing from the radiator, and is independent of the temperature of the room being heated. Disposed above the radiator or heating element 29 is an air-conditioning unit, generally indicated by reference character 34. In the case of an older building, this will normally be a window unit type equipped with a drip pan 35. A conduit 36 interconnects the drip pan 35 in such manner that air-conditioning condensate will flow to the float pump unit 32.

Associated with the float pump unit 31, 32 is a check valve 37 in series with a conduit 38 leading to the fitting 27; the check valve permitting the flow of fluid in a direction to the fitting.

Referring again to the basement level 11, an auxiliary return main 40 is interconnected at the foot of each of the risers 21 and 22 through float and thermostatic traps. The main 40 is provided at the end thereof with a trap 41 similar to the trap 31, and leads to a condensate return unit 42. The return unit 42 is provided with a check valve 43 and is selectively connected by manually closeable valves 44 and 44 to the boiler 17 or a sink 45 connected to the sanitary system of the building. Where the steam main 19 is of substantial length, it is in some instances desirable to substitute an additional fioat pump unit 31, 32 in lieu of the trap 41 to assist in returning the condensate to the return unit 42.

Referring to FIGURE 4 in the drawings, there is shown in greater detail the structure of the fitting 27 employed in conjunction with each radiator 29. The fitting 27 includes a threaded housing 49 having first and second aligned openings 50 and 51 which are internally threaded at 52 to engage portions of the conduit 26. The housing 49 includes a laterally extending projection having a tapered threaded opening 53 therein, the opening 53 being engaged by a correspondingly tapered plug 54 having a threaded bore 55 therein. The bore 55 includes a packing recess and accommodates a second plug 58 having a second bore 59 therein which engages the end portion of the conduit 38. The terminal 60 of the conduit 38 is bent downwardly to lie parallel to the axis of the conduit 26.

Referring to FIGURES 2 and 3, the float pump units 32 attached to each radiator are seen in greater detail. Broadly, the unit includes a condensate collecting element 62 and a pump element 63. The element 62 comprises a housing 65 having a bottom wall 66, a cylindrical side wall 67 and a removable top wall 68. The inlet 69 3 is connected to the trap 31 and is provided with a baffie 70 which directs condensate downwardly into the lower portion 71 of the chamber formed within the housing 65. The condensate outlet 73 is preferably provided with a screen 72. A thermostatically controlled outlet 74 is provided in the top wall 68, the thermostatic valve element 74' being such that the outlet 74 is closed in the presence of steam vapor. The float switch 75 may be of any suitable type, preferably including a mercury capsule 76 which will close an electrical circuit when the level of condensate within the housing 65 has reached a predetermined point.

The pump element 63 may be of well known type, preferably including a centrifugal impeller 78 mounted on a shaft 79 driven by a sub-fractional electric motor 80.

Operation of the one-piece system shown in FIGURE 1 is as follows: During the winter months in which heating is required, steam travels from the boiler 17 through the steam main 19 and risers 20 and 21, past the fitting 27, and to the automatic valve 28. Where there is no demand for heat in the individual space heated by the particular radiator 29, no flow of steam occurs. Upon the opening of the valve 28, steam travels through the valve and radiator where it cools and condenses. As there is a pressure drop in the steam as it passes through the automatic valve 28, the steam can no longer return back to the one-pipe system, i.e. the riser, main and boiler. It is for this reason that automatic valves have not been used in the prior art extensively on one-pipe systems. As the steam cools and condenses, it flows through the outlet 30, the thermostatic or vapor trap 31 and into the float pump unit 32. When sufficient condensate has been ac cumulated, the float switch '75 is actuated, closing the circuit to the motor 80, wherein the condensate is pumped through the fitting 27 and back into the respective riser. From the riser, the condensate flows to the main 19 and thence to the condensate return unit 42 to the boiler.

During the summer months, when the steam system is not in operation and the Window air-conditioners are operating, condensate from the air-conditioner drips from the drip pan 35 through the conduit 36 and the thermo statically controlled passage 74 in the top 68. This passage will normally be open in the summer time to perunit the condensate to flow into the float pump unit, and will normally be open in the winter time as Well, to permit air trapped within the radiators to be vented. Upon the presence of steam, the thermostatic control Will close the passage to prevent loss of steam through the airconditioner drip pan. During the summer, the condensate return unit 42 dumps excess condensate into the sink 45, as valves leading to the boiler are closed.

It may thus be seen that I have invented a novel and highly useful improvement in air-conditioning, heating and ventilating devices and systems, in which there has been simultaneously provided means for disposing of summer-time air-conditioning condensate and increased efiic-iency in the heating operation of one-pipe steam systems. By the employment of a separate pump and return to the riser for each radiator, it is possible to incorporate the advantages of a two-pipe system into a single pipe steam system already existing, namely the presence of an automatic valve, as the problem of drop in steam pressure through the valve is eliminated. In the installation of dihe improved system, a minimum of expensive labor time is involved, and the cost of the individual fioat pumps and riser fittings may be of a reasonably low order, so that the total .cost of installation in even a relatively large building may be reasonable. The efiiciency and comfort obtained from such installation may readily be made to justify such cost.

I Wish it to be understood that I do not consider the invention limited to the precise details of structure shown and set :forth in this specification, for obvious modifications will occur to those skilled in the art to which the invention pertains.

I claim:

1. In a combination heating and cooling system, including a boiler element, a riser connected to said boiler element, and a radiator having an inlet connected to said piser, an air conditioner unit including an evaporating coil and a drip pan disposed beneath said evaporating coil, the improvement comprising: means (for selectively collecting condensate from, and connected .to, said drip pan and said radiator, and pump means connected to said last-mentioned means rfor returning said condensate to said riser; said collecting means including a thermostatically cont-rolled valve providing for the venting of air to the outside atmosphere.

2. In a steam heating system including a boiler ele ment, at least one riser connected to said boiler element, and a plurality of radiators having inlets connected to said riser, the improvement comprising: an automatically thermostatically controlled valve connected to and controlling each of said radiators. means for individually venting said radiators, and collecting steam condensate therefrom, and individual pump means connected to each of said venting means for periodically returning condensate to said riser.

References fitted in the file of this patent UNITED STATES PATENTS 1,086,143 Davidson Feb. 3, 1914 1,115,912 Dodson Nov. 3, 1914 1,177,464 Weschler Mar. 28, 1916 1,592,025 Jennings July 13, 1926 2,028,173 Thomas Jan. 21, 1936 2,056,263 Ehrlich Oct. 6, 1936 2,266,986 Murphy Dec. 23, 1941 2,432,838 Van Zwienen Dec. 16, 1947 2,549,238 Reinke Apr. 27, 1951 2,613,919 Russell et a1. Oct. 14, 1952 2,673,720 Spieth Mar. 30, 1954 2,794,624 Campagna et a1 June 4, 1957 

1. IN A COMBINATION HEATING AND COOLING SYSTEM, INCLUDING A BOILER ELEMENT, A RISER CONNECTED TO SAID BOILER ELEMENT, AND A RADIATOR HAVING AN INLET CONNECTED TO SAID RISER, AN AIR CONDITIONER UNIT INCLUDING AN EVAPORATING COIL AND A DRIP PAN DISPOSED BENEATH SAID EVAPORATING COIL, THE IMPROVEMENT COMPRISING: MEANS FOR SELECTIVELY COLLECTING CONDENSATE FROM, AND CONNECTED TO, SAID DRIP PAN 